Protective Effects of Broccoli (Brassica oleracea) and Its Active Components against Radical-Induced Oxidative Damage

抄録

The radical scavenging effect and protective potential from oxidative damage by radical generator, 2, 2'-azobis (2-amidinopropane) dihydrochloride (AAPH), in renal epi-thelial LLC-PK₁ cell of broccoli (Brassica oleracea) were investigated and identified the active components under the bioassay-linked fractionation method. The McOH extract, and frac-tions of CH₂Cl₂, BuOH and H₂O from broccoli showed the 1, 1-Biphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect in a dose-dependent manner. In addition, they exerted the protective effect against LLC-PK₁ cellular damage induced by AAPH dose-dependently. In particular, the BuOH fraction was evaluated as the most active fraction, indicating that the BuOH fraction contains the active components with antioxidative capacity. Employing a bio-assay-linked fractionation method, the active principles were isolated and characterized as 1, 2-disinapoylgentiobiose and 1-sinapoyl-2-feruloylgentiobiose from the BuOH fraction. These two compounds from broccoli displayed potent antioxidant effects against the DPPH radical, showing the IC₅₀ values of 5, 18 and 7.52 μg/mL, respectively. Moreover, the com-pounds significantly and dose-dependently recovered cell viability lowered by AAPH treat-ment, suggesting the protective roles from cellular oxidative damage. The present study suggests that broccoli has excellent antioxidative potential and the hydroxycinamic acid esters from broccoli, 1, 2-disinapoylgentiobiose and 1-sinapoyl-2-feruloylgentiobiose, are considered as the active components with antioxidative effect.